Wii 4.1e help required

I have a new Wii with version 4.1e software on it. Having looked through some of the posts on the hacks, I am more confused now than before.
I think it is info overload in some aspects, the questions I have is this -

1 It says never to upgrade the software from the Wii web site is this correct

2 What do I need to do to enable my Wii to be able to play games from a external USB harddrive and how do I go about this ( I am confused in respect to this)

3 Is it easier to use backup disks in the drive than a harddisk

4 Looking at some of the posts we use a SD card what software is on this and does it remain in the slot at all times .

you missed to say Hello in the introduction sectio.
and you have to do a little bit more reading.. i know its an overload but nessecary
see the Basic link below. will answer most of your questions.

1) never update via Nintendo, no need to have a high firmware version
2) softmodding your wii, owning a hdd.
3) newer wiis can't play burned media. really a pain, check out wiiflow or cfg usbloader on youtube (3.1) never use a youtube softmod guide=instant fail)
4) if you use the fat32 loading guide you can have the apps on your hdd, its not needed to have the sd in all the time, but helps sometimes.

say Hello , do a lot of reading before starting over. and use the search function or google with: keyword site:wiihacks.com
good luck